The progression of features and performance of portable wireless communications devices, such as cellular telephones, PDAs and the like, has occurred at an almost exponential rate since the devices were first introduced into the consumer market. Manufacturers are constantly working to reduce the size, extend battery life, and increase communication reliability and range. In addition, the devices now commonly have features such as picture, video, and sound recorders, organizers, synthesized ring tones, email and text messaging service, video games, and others.
Ironically, as phone manufacturers have worked to achieve longer and longer transmission distance capabilities, one new feature that can currently be found in some devices, but is being developed for more widespread use, is close-range data transferring capability. That is to say, it is desirable that the device is not able to send certain types of signals very far. One use of this feature can be, for instance, to communicate one's credit card information to complete a retail purchase. Ideal transmission in this mode is a very short distance, usually no more than four feet.
For this short-range transmission, an additional antenna is used. Preferably, this antenna will be conformal and not increase the size of the device package. Several manufactures have attempted to place the near-field antenna in the battery compartment or near the battery of the device. However, these prior-art solutions require additional terminals to connect and energize the antenna element, thereby necessitating that the device hardware be redesigned.
Those that have been able to use existing terminals require a complicated multiplexing scheme where use of the terminal is shared by time switching so that only one signal is present at a given time.
Therefore a need exists to overcome the problems with the prior art as discussed above.